Firmware: Tom E’s open-source GPL NarsilM v1.3 adapted by Texas_Ace
User interface:  By default the GT Nano is set to use the very intuitive Narsil smooth RAMPING UI. Instant access to a 2.5A TURBO mode is also provided.
 A more conventional discrete level MODE-SET UI is available as an alternative. Any one of 12 pre-defined mode-sets can be selected.
 MOMENTARY mode is useful for signaling purposes or rapidly/briefly lighting up targets.
Emitter: CREE XPG3 (6500K), SST20 (4000K)
Flux: ~ 1620 lm
Throw: ~ 165 m &, ~ 6795cd
Battery: One 10440 Li-ion battery (not included).
Driver: Texas Avenger FET driver
optics: standard TIR lens
Lens: Glass with anti-reflective coating
Body: Aluminum with Type III hard-coat anodizing
Button: Tactile with back-lit rubber boot
Ingress rating: Equivalent to IPX-8, underwater 2m
Weight: Approximately 30g without cells
Dimensions: 170mmx 24mm x 14mm
1*GT Nano Pro Flashlight